fix(text_editor.py): handle out of bounds start line by returning empty content instead of raising an error

test(text_editor.py): add unit tests for reading ranges with out of bounds start lines to ensure correct behavior

Author: tumf

src/mcp_text_editor/text_editor.py

@@ -112,9 +112,18 @@ async def read_multiple_ranges(
                     )
 
                     if line_start >= total_lines:
-                        raise ValueError(
-                            f"Start line {line_start + 1} exceeds file length {total_lines}"
+                        # Return empty content for out of bounds start line
+                        result[file_path].append(
+                            {
+                                "content": "",
+                                "start_line": line_start + 1,
+                                "end_line": line_start + 1,
+                                "hash": file_hash,
+                                "total_lines": total_lines,
+                                "content_size": 0,
+                            }
                         )
+                        continue
                     if line_end < line_start:
                         raise ValueError(
                             "End line must be greater than or equal to start line"
@@ -172,7 +181,7 @@ async def read_file_contents(
             line_end = len(lines) if line_end is None else min(line_end, len(lines))
 
             if line_start >= len(lines):
-                raise ValueError("Start line exceeds file length")
+                return "", line_start, line_start, file_hash, len(lines), 0
             if line_end < line_start:
                 raise ValueError("End line must be greater than or equal to start line")
 

tests/test_text_editor.py

@@ -309,4 +309,35 @@ async def test_read_multiple_ranges(editor, test_file):
     assert second_range["content"] == "Line 2\nLine 3\nLine 4\n"
     assert second_range["start_line"] == 2
     assert second_range["end_line"] == 4
+
+
+@pytest.mark.asyncio
+async def test_read_multiple_ranges_out_of_bounds_start(editor, test_file):
+    """Test reading ranges where start line exceeds file length."""
+    ranges = [
+        {
+            "file_path": test_file,
+            "ranges": [
+                {"start": 1000},  # Way beyond file end
+                {"start": 6},  # Just beyond file end
+            ],
+        }
+    ]
+
+    result = await editor.read_multiple_ranges(ranges)
+
+    # Check first range (start line way beyond file end)
+    first_range = result[test_file][0]
+    assert first_range["content"] == ""
+    assert first_range["start_line"] == 1000
+    assert first_range["end_line"] == 1000
+    assert first_range["total_lines"] == 5
+    assert first_range["content_size"] == 0
+
+    # Check second range (start line just beyond file end)
+    second_range = result[test_file][1]
+    assert second_range["content"] == ""
+    assert second_range["start_line"] == 6
+    assert second_range["end_line"] == 6
     assert second_range["total_lines"] == 5
+    assert second_range["content_size"] == 0